This disclosure relates to the brazing of two or more components. In particular, this disclosure relates to component structures for controlling the flow of brazing material between the components and methods related to forming and using said structures to provide stronger brazements between the components.
Brazing is a process by which two or more metallic components may be joined to one another. The brazing process often begins with a solid brazing material being placed in a reservoir that is in fluid communication with a volume between the surfaces of the components to be joined. The brazing material has a low melting temperature such that, when the brazing material is heated, the brazing material forms a liquid phase that fills the volume between the two components. Typically, gravity and capillary action are used to transport the liquid phase of the brazing material from the reservoir to the volume between the two components.
The liquid phase of the brazing material contacts and wets the surfaces of each of the components. This contact between the liquid phase of the brazing material and the metallic surfaces to be joined dissolves a thin layer of each of the metallic surfaces. The liquid phase of the brazing material and the dissolved component metals form a liquid alloy. Upon solidification, the liquid alloy forms a bond between the components, thus joining them.
The strength of the brazed joint may be compromised if the brazing surfaces are not properly wetted by the brazing material. Improper wetting may occur if the distance between the surfaces to be brazed is irregular or if there is not enough brazing material to fill the gap between the components. If the brazing material does not completely fill the gap between the components, then this defect weakens the brazed joint and makes it more susceptible to mechanical failure.
As the assembled, but not yet brazed, components are typically handled before brazing, some misalignment of the components is common. Such misalignment can alter the uniformity and the consistency of the spacing of the components, adversely affecting the wetting of the surfaces during brazing and creating the potential for loss of some of the brazing material via overflow.
Further, if mishandling has severely misaligned the components, then the overall dimensional requirements for the final brazed part may not be met, meaning that the part will need to be scrapped or subjected to costly post-brazing secondary operations.
Hence, a need exists for improvements in the brazing process to provide mechanically strong brazed joints. In particular, there is a need for better control over the brazing material during the formation of the brazed joint.